GeForce GT 640M and GeForce 820M - video card comparison
Passmark - benchmark score GeForce GT 640M vs GeForce 820M
GeForce GT 640M
943
GeForce 820M
511
GeForce GT 640M
GeForce 820M
Architecture
Kepler (2012−2018)
Fermi (2010−2014)
GPU code name
N13P-GS
N15V-GM
Market segment
Laptop
Laptop
Release date
March 2012
January 2014
Bus support
PCI Express 2.0, PCI Express 3.0
PCI Express 2.0
Interface
PCIe 3.0 x16
PCIe 2.0 x16
Boost clock speed
645 MHz
-
Core clock speed
Up to 625 MHz
775 MHz
CUDA cores
384
-
Floating-point performance
480.0 gflops
240.0 gflops
Manufacturing process technology
28 nm
28 nm
Number of transistors
1,270 million
585 million
Pipelines / CUDA cores
384
96
Power consumption (TDP)
32 Watt
15 Watt
Texture fill rate
Up to 20.0 billion/sec
10.00
Memory type
DDR3\GDDR5
DDR3
Maximum RAM amount
2 GB
2 GB
Memory bus width
128bit
64 Bit
Memory clock speed
1800 - 4000 MHz
1800 MHz
Memory bandwidth
Up to 64.0 GB/s
14.4 GB/s
Shared memory
-
-
Display Connectors
No outputs
No outputs
HDMI
+
-
HDCP
+
-
Maximum VGA resolution
Up to 2048x1536
-
DirectX
12 API
12 (11_0)
CUDA
+
+
OpenCL
1.1
1.1
OpenGL
4.5
4.5
Shader Model
5.1
5.1
Vulkan
1.1.126
N/A
3D Blu-Ray
+
-
GameWorks
-
+
GPU Boost
-
2.0
Optimus
+
+